Microfluidic devices have been used in radiochemistry since about 2004. A recent review by Elizarov (ibid.) summarizes the various approaches that have been taken. It is a common view in the field that the use of microfluidics has many advantages over the predominant macroscopic methods (manual and automated systems) for the production of PET tracers.
In regard to microfluidics, most researchers have used continuous flow microreactors (Elizarov (ibid.)) that still require substantial auxiliary equipment such as syringe pumps, F-18 drying subsystems, etc. As a result, these systems are bulky, complex, and expensive. The few “integrated” approaches (C.-C. Lee, G. Sui, A. Elizarov et al., “Multistep Synthesis of a Radiolabeled Imaging Probe Using Integrated Microfluidics,” Science, vol. 310, no. 5755, pp. 1793-1796, Dec. 16, 2005) that have been tried suffer from material compatibility problems. For example, PDMS is not compatible with many organic solvents and other reaction conditions used in probe syntheses. Further, very low reliability of operation has been observed. Integrated approaches all use microfluidic devices with well-defined channel patterns. This restricts flexibility and in most cases, requires that different probes use different chip designs.